Abstract

The National Lighting Product Information Program (NLPIP) at Rensselaer Polytechnic Institute's Lighting Research Center (LRC) purchased 14 streetlights, identified by a specifier survey, between July and October 2009. Four used high pressure sodium (HPS), one used induction, eight used light-emitting diodes (LEDs), and one used pulse-start metal halide (PSMH) light sources. NLPIP determined how many of each type of streetlight were needed to illuminate 1.0 mile (1.6 kilometer [km]) of a collector roadway to meet the design criteria specified by the American National Standards Institute (ANSI)/Illuminating Engineering Society of North America (IESNA) RP-8-00 (R2005), the American National Standard Practice for Roadway Lighting (referred to as RP-8 below). NLPIP then calculated power demand and costs per mile.

NLPIP found that:

On average, the LED streetlights and the induction streetlight could be spaced only about one half the distance of the HPS and PSMH streetlights and still meet the RP-8 lighting criteria. If an HPS or PSMH streetlight system just meeting RP-8 is replaced with the LED or induction streetlights tested in this report on a one-for-one basis, the streetlight system will not meet RP-8.

The life cycle cost per mile is dominated by the initial and installation cost of the poles, not the initial cost of streetlights or any potential energy or maintenance cost savings. Because of the narrower pole spacing required to meet RP-8, the life cycle cost of the LED streetlights tested for this study is up to twice that of the HPS and PSMH streetlights tested.

On average, the LED streetlights require 1% and 10% less power per mile than the HPS streetlights tested in staggered and single-sided layouts, respectively. On average, the LED streetlights require 8% and 24% less power than the PSMH streetlight tested in single-sided and staggered layouts, respectively.

The street-side lumens metric is a useful parameter for comparing streetlight layout costs.

At the illuminance levels typical of collector roadways, power requirements for "white light" sources are 3% to 19% lower than HPS sources based on models of mesopic photometry.

* NLPIP's response to comments made about this publication can be viewed here.